Mechanical time fuse



NOY. 6, 1934. A, VARAUD 1,979,426

MECHANICAL TIME FUSE Filed Feb. 5. 1955 fig. 2.

f vewfor i fl n re Patented Nov. 6, 1934 PATENT oFFicE MECHANICAL TIME FUSE Andr Varaud, Geneva, Switzerland Application February 3, 1933, S'erialNo'. 655,133

' In Switzerland February 1932 4 Claims. (01. 102-36) in. which a member integral with the cap moves.

in relation to the latter under the effect of inertia and at the moment of the firing, establishing by said movement a connection between the said cap 5 andbody'of the fuse, which connection continues from the moment that it has been established.

The members used for the connection are, for example, wedges or spikes, and their adjustment being efiected for small accelerations, they very often do not remain in position under the action of inertia resulting from the shocks of transport.

so as to bring it into contact with the toothed These members are in fact most often kept'in place by Weak elastic members, which they quit by inertia atthe moment of the firing or else when a shock producedin the course of'transport draws them away. The latter efiect, which may be called an accident, but which has been observed in practice, has the great inconvenience of. affecting the timing at the moment of em'-- .25.; ployment.

The fuse according to. the invention disposes of that inconvenience through the fact that it possesses a crown of ratchet or one-way teeth on the body of the fuse with which teeth co-operates at least one plate or shoe movable in the axial direction in the adjustment ring, providedwith corresponding. teeth and so arranged that at t e discharge of the shot it is caused by inertia to engage in the toothed crown,means being provvided for this action to take place onlyduring' the linear acceleration andth'at the friction alone of the cap may maintain the adjustment "during thetrajectory of the projectile.

Thus the connection between the cap and the body of the fuse is only produced at the moment of an acceleration, but does not continue when once said acceleration is ended. If therefore the fuse according to the invention is subjected to a shock during transport, it is quite possible that such shock may in certain cases displace the shoe crown. But when once the effect of the shock is terminated, the support will resume its original position in which it in no way opposes the timing of the fuse.

At the moment of the firing and when once the linear acceleration is terminated, that is to say during the trajectory, the friction alone of the cap on the body will sufiice to maintain the ad-.

justment, all the more as means can be provided ensuring an invariably regular friction, as will be seen from the following description.

The drawing represents, by way of example, a fuse according to the invention. 7

Fig; 1' is an outer view of the fuse surmounted by the ring and a cap.

Fig. 2 is a verticalaxial section of the fuse of Fig.1.

Fig. 3 isa view from belowof the adjustment ring, the. upper half of this figure illustrating a modification and the lower half another modification of the said ring.. I

Fig- 4 is a View from above of the body only of the fuse.

Fig; 5. is a detail of thefirst modification, and

- Fig. 6- is adetail of the'second modification of- Fig. 3.

Figs. '7 and 8 show an example of operation of the modification according to the detail of Fig; 5.

With reference toFig. 1, the fuse body properly so-called is represented at 1, at 2 is represented the adjustment ring; mounted with friction upon it and at 3the. oapintegral with the said adjustment ring.

Thesethreemembers are seen in section in Fig. 2 whichfurther shows, at 4, the movement on Which-the adjustment ring 2-acts by'means of the arm- 5, also visible in Fig. 3, said movement being partly removed. v

The ring 2 isheldonthe body 1 by means of an inner annular nut 6 andwith interposition of a pressure ring 7, likewise visible in Fig. 4 where, inaddition to the body 1,1this ring together with themovement 4 seen from above are represented, the annular nut 6,'the ring 2and the cap B'being supposed to be removed. The ring 7 has two lugs 8 entering'int'o corresponding notches 9 of the screw-thread lO'of-the body 1'. I

Thus this ring 7 cannot rotate and consequently cannot transmit to the annularnut 6 when once tightened, any angular movement capable of displacing it, that is to say of increasing or decreasing the efiect of its tightening. Under this ring 7 is placed an elastic member 11 intended to exert a constant pressure on the adjustment ring 2 tightened by these members. This adjustment ring rests on the body with an air-tight joint 12 interposed.

The tightening obtained by the construction just described is secure from being put out of order and suffices to maintain the adjustment of the ring during the whole duration of the trajectory. It is not, on the contrary, sufiicient to hinder an angular displacement of the adjustment ring 2 and of the cap 3 through inertia of rotation, when at the moment of discharge of the shot, the body 1 suddenly starts rotating at high speed according to the inclination of the rifling grooves.

For the purpose of establishing the connection necessary for preventing such an angular displacement in the direction contrary to'the rota tory movement of the projectile, the body 1 is provided withacrown 13 having teeth of ratchet type directed against the surface of the ring 2.

The ring 2 itself, as shown by the upper half of Fig.3, has. seen from below, a certain number of 17 holding it hooked in therecess which is under-.

cut for this purpose in the way shownin Figs. 5

and 7. a

With reference to the lower half of Fig. 3, the

toothed plates are kept in place by outer springs '18placed in grooves of the ring 2 and bearing on the plates, each spring holding one end of two supports, as shown in Fig.6. The method of fixing the toothedplates must be elastic to allow a cess andengagethetoothed crown 13 of the body 1.

This is done, for example, in the manner shown in Fig. 8, when upon discharge of the shot the projectile is suddenly borne forward in the direc tion of the arrow 19 andthe plate 15 through inertia. does not immediately take part in this movement and, consequently, comes to engage the teeth of the crown 13 by slightly bending the elastic member, say the blade 1'7, which retains it. Rotary displacement of the ring 2 andbody 1 is rendered impossible in the direction of the acceleration of the rotatory movement of the projectile, if care has been taken to place the teeth in the right direction. Aslong as this acceleration prevails the plate and the toothed crown remain in engagement and when once the acceleration is ended, these members become disengaged, which has then no detrimental effect.

By the irregular pitch of the toothed plates, it is assured that at least one of these plates will always lie in position to engage eflectively the teeth of the crown at the instant of discharge.

It is clear that there can be any number of toothed plates, as well as of lugs of the ring 7,

also that the toothed crown ma be integral with the body 1 or a separate member fitted thereto. I I

What I claim as my invention and desire to secure by Letters Patent of the United States is:-

1. A mechanical time fuse comprising a fuse body adapted to be secured to a projectile, a

timing adjustment ring rotatable on the body,

means ensuring constant frictional resistance to rotation of the ring on the body, toothed means operated by inertia whenthe projectile is subiected to an accelerating force of projection for positively engaging teeth on the body to lock the ring against rotation thereon during acceleration of the projectile, and spring means normally holding the toothed means inoperative, said spring means yielding under the inertia of the toothed means to render, the toothed. -means operative.

2. A mechanical time fuse comprising a body adapted to be secured to a projectile and-having a ring of one-way acting crown teeth, a timing adjustment ring rotatable on the body, means ensuring constant frictional resistance to rotation.

of the ring on the body, a plurality of plates with similar one-way acting teethcarried by the ring in alinement. with the crown teeth of the body,

but capable of yielding under inertia forces on said plates set up upon acceleration of the projectile to permit temporary and self releasing engagement of said plates with said teeth.

3. A mechanical timing fuse according to claim '2, in which the toothed plates are irregularly pitched around the adjustment ring, the irregularities of pitch being determined to create phase differencesol less than onetooth pitch in the engagement of different toothed plates with the crown teeth.

4. A mechanical timing fuse comprising a body adapted tobe secured to a projectile and having a ring of one-way acting crown teeth, a timing adjustment ring rotatable in either direction on the body, means including a screw-tightened pressure ring for holding the adjustment ring on the body incapable of axial movement thereon but ensuring constant frictional resistance to rotation of the ring on the body, a plurality of toothed plates carried by the ring in alinement with the crown teeth of the body, and spring means normally holding the toothed plates out of engagement with the crown teeth but capable of yielding under inertia forces on said plates set up upon acceleration of the projectile to permit temporary and self-releasing engagement of said plates with said teeth.

ANDRE VARAUD. 

